Aluminum compounds



permitted to move downward by the action of its spring 60, causing turning movement of the shaft 3| into the full charge position. It is to be noted that full charge then is obtained only if the lever 40 is in full charge position with respect to the segmental rack 4|. In case this lever is not in full charge position but in an intermediate charge position, then such intermediate charge only is obtained with respect to the first group of cylinders. During starting the shaft 35 is prevented from turning movement, due to the play between the clutch members 36 and'3l and because the second hand-lever 43 engages the segmental rack 44 and thereby holds the second shaft 35 from turning. No change at first as regards the operating condition of the second pumps takes place when finally the hand-wheel 58 is moved into normal operating position. The spring 60 tends to urge the rod 53 downward to follow the contour of the cam 56, but due to the fact that the lever 43 engages the segmental rack, the rod 53 is prevented from moving to its lower limit of travel and the second shaft 35 is still prevented from turning. In order to adjust the second group of pumps M for fuel supply after the starting air is shut off, it is necessary to move the lever 43 manually from zero charge to charge position. Thus with my invention, movement of the second shaft by the lever 43 from zero to full charge position is carried out manually and permits controlling or securing the charging of certain cylinders. The second group of cylinders is brought to full charge slowly and gradually to avoid too sudden temperature changes of these cylinder liners and heads.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In a multi-cylinder combustion engine, the combination of a first cylinder, a second cylinder for receiving starting air, means for supplying fuel to both of said cylinders, means for controlling the fuel supply to said first cylinder, means for controlling the fuel supply to said second cylinder, both of said means being biased to full charge position and coupled by a lost motion device whereby said second control means is normally operable only after said first control means, and'means for securing said second control means against normal operation, said securing means being operable to control the charging of said second cylinder.

2. In a multi-cylinder combustion engine, the combination of a first cylinder, a second cylinder, means for conducting compressed air to the second cylinder during starting, means for supplying fuel to the cylinders .and controlling the fuel supply comprising a pump for each cylinder and a regulating shaft for each pump, means for controlling said shafts to supply fuel to the first cylinder immediately during starting and to the second cylinder after ignition in the first cylinder, and means for securing said second regulating shaft against operation in response to said controlling means.

3. In a multi-cylinder combustion engine, the combination of a first cylinder, a second cylinder,

means for conducting compressed air to the secmeans, said last named means comprising a coupling. having a member connected to the regulating shaft for the first cylinder and another member secured to the regulating shaft for the second cylinder, said members engaging each other and having an amount of play sufiicient-to permit full fuel supply to the first cylinder without effecting fuel supply to the second cylinder.

4. In a multi-cylinder combustion engine, the combination of a first cylinder, a second cylinder, means for conducting compressed air to the second cylinder during starting, means for supplying fuel to the cylinders and controlling the fuel supply comprising a pump and a regulating shaft for each cylinder, regulating means for causing fuel supply to the first cylinder immediately during starting and to the second cylinder after ignition in the first cylinder, means for securing the regulating shaft for the second cylinder against operation in response to the regulating means, said last named means comprising a coupling having a member connected to the regulating shaft for the first cylinder and another member secured to the regulating shaft for the second cylinder, said members engaging each other and having an amount of play sufficient to permit full fuel supply to the first cylinder without effecting fuel supply to the second cylinder, and means for manually limiting the fuel supply to both cylinders comprising a lever connected to the regulating shaft of the first cylinder and a segmental rack for holding said lever in position.

5. In a multi-cylinder combustion engine, the combination of a first cylinder, a second cylinder, means for conducting compressed air to the second cylinder during starting, means for supplying fuel to the cylinders and controlling the fuel supply comprising a pump and a. regulating shaft for each cylinder, regulating means for causing fuel supply to the first cylinder immediately during starting .and to the second cylinder after ignition in the first cylinder, a coupling having a member connected to the regulating shaft for the first cylinder and another member secured to the regulating shaft for the second cylinder, said members engaging each other and having an amount of play sufficient to permit full fuel supply to the first cylinder without effecting fuel supply to the second cylinder, means for securing the regulating shaft for the second cylinder against operation in response to the regulating means comprising a lever secured to the regulating shaft for the second cylinder and a segmental rack having a few teeth for holding the regulating shaft for the second cylinder in position in and near zero charge, a manual control lever for turning the regulating shaft for the first cylinder, and means connected to the regulating shaft for the first cylinder for automatically controlling the fuel supply.

FRIEDRICH SASS.

Patented Oct. 22, 1935 UNITED STATES PROCESS OF OBTAINING BEILYLLIUM AND ALUMINUM COMPOUNDS Charles B. Sawyer and Bengt Kjellgren, Cleveland Heights, Ohio, assignors to The Brush Beryllium Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Original application October 14, 1930, Serial No. 488,662, now Patent 1,823,864, September 15, 1931. Divided and this application May 11, 1931, Serial No. 536,518. In Canada January 6, 1927 Claims.

This invention relates to a process of separating beryllium sulphate from mixtures thereof with other salts. The process has been developed more particularly in connection with the recovery of beryllium from the ore beryl and the present application is a division of our earlier copending application Serial No. 488,662, filed October 14, 1930 (Patent No. 1,823,864, granted September 15, 1931), which constitutes a continuation in part of our earlier filed applications Serial No. 5,169, filed January 27, 1925, and Serial No. 123,- 593, filed July 19, 1926. Our entire process of recovering the beryllium from the ore comprises 1 two main stages, namely, (1) the conversion of the beryllium and aluminum naturally occurring in the ore into soluble salts of said metals and (2) the treatment of said salts to effect the separation of the beryllium from the aluminum and other constituents. Our Patent No. 1,823,864 relates to the first stage of the entire process and the present invention has -to do with the second stage, although it is to be understood that it is not limited in its application to the recovery of beryllium from its ores.

An object of the invention is to provide a process of separating beryllium sulphate from mixtures thereof with aluminum and other sulphates by which beryllium salts of a high degree of purity can be produced.

A further object of the invention is the provision of a process particularly adapted to the separation of beryllium sulphate from mixtures thereof with aluminum and other sulphates as obtained by sulphatizing ores of beryllium, such as beryl.

Other objects of the invention will be apparent to those skilled in the art from the description of it hereinafter given.

In our process of recovering the beryllium content from the ore beryl, as set forth in our Patent No. 1,823,864, the beryl preferably is treated to render it more susceptible to attack by reagents, such as sulphuric acid. This is accomplished by heating the beryl above 1000 C., and preferably to the melting point, and then rapidly cooling, as by quenching in water. When the thus modified beryl is treated with sulphuric acid,.sulphates of all the basic oxides present in the ore are formed, such as beryllium, aluminum, iron and alkali sulphates. In the following description it will be assumed, by way of example, that such a mixture of sulphates is to be treated by the process constituting the present application.

After treatment of the modified beryl with sulphuric acid we prefer to extract the sulphates from the sulpbated material so as to make an aqueous solution of the sulphates. From this solution the aluminum sulphate may be completely separated by converting it into an alum, for example ammonia alum. by adding a suflicient 5 amount of ammonium sulphate, and subsequently removing the alum by crystallization. It has been known that a major portion of the aluminum can be separated from the other sulphates as an alum, but heretofore it has never been poso sible to secure a complete separation. According to the present invention a complete separation is attained by either of two methods, both of which are based on the discovery that an alum,

such for example as ammonia alum or potassium 15 alum, is substantially insoluble in an aqueous solution containing a mixture of beryllium sulphate and an alkali sulphate, such for example as ammonium sulphate or potassium sulphate, provided that the concentration of the solution with re- 0 spect to both the beryllium sulphate and the alkali sulphate is sufilciently high at the temperature of the solution. A saturated solution of beryllium sulphate dissolves some ammonia alum at room temperature. If, however, ammonium 25 sulphate is added the solubility of ammonia alum in this solution rapidly decreases and is practically zero at about 18 C. (room temperature), when the amount of ammonium sulphate approaches about 6% of the weight of beryllium sul- 3 phate (BeSOr-4Hz0) in solution. If the beryllium sulphate solution is not saturated a greater amount of ammonium sulphate has to be added. Also if the temperature of the beryllium sulphate solution is increased, more ammonium sulphate 35 has to be added.

In one of the two above-mentioned methods of carrying out the present invention, the ammonium sulphate is added in suitable excess to the solution of mixed sulphates and the solution 0 is concentrated to such a degree that theammonia alum formed and separated by crystallization is insoluble in the remaining mother liquor, from which the alum is readily separated, for example, by filtration. For practical purposes 5 it is preferable, in forming the alum, to dissolve in the aqueous solution containing the beryllium and aluminum sulphates an excess amount of ammonium sulphate equal to 10-20% of the weight of the beryllium sulphate (BeSO4-4HzO) present in the solution in order to secure a suitably wide usable range of concentrations and temperatures. If the excess amount of ammonium sulphate used be less than about 6% of the weight of the crystalline beryllium sulphate the alum may still be substantially completely separated by cooling the solution to temperatures lower than ordinary room temperatures. on the other hand it is possible to use very high percentages oi ammonium sulphate (limited, obviously, by the solubility of the alkali sulphate in the beryllium sulphate solution), but it is, oi course, preferable to use as little ammonium sulphate as is practically possible. Obviously, any predetermined high degree of separation less than complete separation, as well as complete separation, of the aluminum sulphate (as alum) from the beryllium sulphate, can be eflected by adjusting the concentration, or temperature, or both concentration and temperature, of the solution containing the three mixed sulphates.

If the fullest benefit of the invention is sought, the concentration of the beryllium-aluminum sulphate solution with respect to beryllium sulphate should be such on cooling after the addition of the excess alkali sulphate as to closely approach the saturation point, and practically this can readily be insured by so adjusting the specific gravity of the beryllium-aluminum sulphate solution that on cooling after addition of the excess alkali sulphate a small amount of beryllium sulphate is crystallized out with the alum.

The second of the two above-mentioned methods for carrying out the invention is similar to the first method except that use is made of an alternative procedure for the separation of the beryllium sulphate from the alum. In this second procedure the beryllium-aluminum sulphate solution is treated with an amount or ammonium sulphate sufllcient to form an alum. After the addition of the alkali sulphate the solution is further concentrated until a mixture of beryllium sulphate and alum crystals is obtained, for example by cooling. The mixture of crystals is further separated by filtration and then is leached with a solution of beryllium sulphate and ammonium sulphate, the ammonium sulphate being used in an amount depending upon the concentration and temperature of the leaching solution and corresponding to the excess amount of ammonium sulphate added to the mixture 01' beryl-. lium and aluminum sulphates in the first described method. Such a leaching solution may contain, for example, 250 grams oi beryllium sulphate (BeSO4-4HzO) per liter and 60 grams of ammonium sulphate per liter. A solution of this concentration is capable of extracting about 570 grams of beryllium sulphate per liter at 20 C. from a mixture of beryllium sulphate and alum without dissolving the alum. Alter extraction, the solution thus contains 820 grams of beryllium .sulphate and 60 grams of ammonium sulphate,

the latter corresponding to an excess of 7.3% of the weight of the beryllium sulphate (BeSOviHaO) in solution.

The leaching process is carried out by stirring the mixed crystals preferably at room temperature or lower temperatures with the leaching so- It will, of course, be understood that in the use of the leaching solution in the second method the interdependent relations between the concentration of the leaching solution with respect to beryllium, the excess of alkali sulphate and the 5 temperature at which the leaching solution is used have the same significance as in the case of the first method and the concentration of the leaching solution with respect to the beryllium sulphate content is to be adjusted in relation to the excess of alkali sulphate and the temperature in accordance with the principles above explained.

By such adjustment of the concentration, excess of alkali sulphate and temperature in carrying out our process by either method of procedure, we are enabled to eilfect a substantially complete separation of the aluminum sulphate from the beryllium sulphate, whereas in prior methods known to us in which the aluminum sulphate is separated 'from the beryllium sulphate in the form of an alum the said separation has been far from complete. Furthermore, as has been indicated, our improved method can be employed not only to efiect complete separation oi the alul8 minum sulphate from the beryllium sulphate, but also to effect any predetermined high degree of separation less than complete separation yet substantially greater than has been attained by prior methods.

After separating the ammonia alum by either of the above procedures, the solution contains a mixture of beryllium, ammonium, iron and possibly alkali sulphates. The beryllium sulphate may be separated from this solution by crystalll lization. To permit such crystallization to the best advantage, the solution should have the iron present in its ferrous condition. And if the iron is not so reduced, it should be reduced at this point by any well known process, such as the in- 0 troduction of sulphur dioxide or barium sulphide.

The mother liquor from the alum crystallization can be concentrated to such degree that on cooling, beryllium sulphate readily crystallizes out in substantially pure form,'leaving any iron I or other impurities in solution. However, it much iron is present it may be necessary, in order to .this recrystallization of the beryllium sulphate can be reused until the iron content becomes too high for the purification of the beryllium sulphate, when the solution may be added to the previous mother liquor and the iron removed therefrom.

It will be seen that whichever of the two procedures for, separating the alum is used, there is 00 involved essentially the use of a solution of beryllium sulphate and an alkali sulphate which contains a suflicient amount of alkali sulphate and which is sufilciently concentrated with respect to the beryllium sulphate to render the alum in- 66 soluble to any'predetermined high degree in the said solution.

The iron which remains in the mother liquor from the beryllium crystallization may be largely removed therefrom in any one of several ways, 70 such as, for example, by further concentration of the mother liquor and crystallizing out of iron sulphate.

The final mother liquor remaining from the iron crystallization contains substantially all the 15 

